Normally, within the framework of the rolling bearings, which the present invention will refer without thereby losing generality, the seal assemblies include an annular screen having a sleeve portion, which is coupled with a rotating annular element, in particular a bearing ring, by means of a mounting by interference in order to render angularly and axially integral with each other the annular screen and the rotating annular element.
Such fittings for interference occur, normally, by placing on the annular shield, or on a part of it, an axial thrust linearly increasing intensity with increasing progressively in surface engagement between the sleeve portion and the rotating annular element. The annular screen is normally realized in a printed metal sheet and sheared so that, after assembly, the sleeve portion showing resiliently compressible against the seat assembly, and such that the radial compression of the sleeve portion exerted on the mounting seat causes a reaction force of the cylindrical surface of sufficient material to prevent any sealing of the screen shifts.
Despite the precision in the positioning and in the assembly of annular screens of the seal assemblies, coupling systems of the type described above have not proved sufficiently reliable in terms of use, or under mechanical and thermal stress, having been found during some tests and operations of maintenance of the movement, albeit minor, the screens themselves than in the bearing rings, or with respect to the nominal design conditions.